20th Regiment

• 20th Arkansas Infantry Regiment
• 20th Connecticut Infantry Regiment
• 20th Continental Regiment
• 20th Duke of Cambridge's Own Infantry (Brownlow's Punjabis)
• 20th Field Artillery Regiment (United States)
• 20th Field Artillery Regiment, RCA
• 20th Hussars
• 20th Illinois Infantry Regiment
• 20th Indiana Infantry Regiment
• 20th Infantry Regiment (United States)
• 20th Iowa Volunteer Infantry Regiment
• 20th Kansas Militia Infantry Regiment
• 20th Lancers (Pakistan)
• 20th Light Dragoons
• 20th Maine Volunteer Infantry Regiment
• 20th Marine Regiment (United States)
• 20th Michigan Volunteer Infantry Regiment
• 20th New York Volunteer Infantry Regiment
• 20th Pennsylvania Infantry
• 20th Regiment Kentucky Volunteer Infantry
• 20th Regiment Massachusetts Volunteer Infantry
• 20th Regiment of Bengal Native Infantry
• 20th Regiment of Foot
• 20th Surveillance and Target Acquisition Regiment, Royal Australian Artillery
• 20th Tennessee Infantry Regiment
• 20th Virginia Infantry
• 20th Wisconsin Volunteer Infantry Regiment